[ngxflyer213]

I have installed a GRT SportSX and Trio Pro Autopilot with Airinc429 adapter and need help testing, configuring, and comfriming my installation is correct.

The Trio AP alone seems to test okay, The TRK and ALT HLD lights illlumnate on power up after entering the field alt. The GPSS illuminates but the GPSV (only blinks) for some reason does not. The HNAV and VNAV lights illuminte when engaged.The control sticks respond correctly when their respected servo is tested in the configuration menu or in CRS mode and inputing left or right of the course.

The EFIS flight Director responds in the horizontal modes such as HDG and ENAV (from a VOR course). The Vertical mode accepts a new altitude, but VS window does not change, always shows +300 below the altitude status on left side of EFIS display


My first question since I am not using a GRT A/P, what is the proper way to engage the AP to be controlled from the EFIS? I don't see any engage soft keys that the GRT AP manual shows with their AP installed. Do I just select the LAT and or VERT mode and then engage the Trio HVAV and VNAV buttons?

Second question during testing with AP servos engaged, should the control sticks follow the FD commands on the EFIS on the ground?


Third question how do you select "no" mode (Horizontal or Vertical) from the EFIS AP menu, I can only change from HDG to ENAV and such but not select VERT or HORZ mode?


I presently only have been able to feed the AP with Autopilot AVIATION MAP and not NEMA0183 (the EFIS has a built in GPS) and is not showing any NEMA 0183 to the ELT beacon or MVP-50 with those set to receive 9600 baud (these are fed from pin 32 of the SportSX)


Looking forward for any help

Dave H

 

[BobTurner]

The easy one: there are no on/off autopilot controls on the efis when used with an external autopilot. As you guessed, you engage horizontal and vertical modes, individually, by pushing the Hnav and/or Vnav buttons on the autopilot.
GPSV is when the autopilot is receiving vertical commands from the GPS on an approach, e.g. Glide slope. Since your GPS is not an approach approved box, gpsv will not work on GPS approaches. I believe but am not certain that the Sport will make an ILS glide slope 'look like' a GPS one, so the gpsv should work when your nav receiver is getting a good GS signal (and you have selected ILS in the autopilot menu).
Make sure you have run 3 control wires - one serial line plus the ARINC pair. It needs all 3 to work properly.
If all 3 are hard wired then the EFIS will always control the Trio. To control the Trio directly, without the EFIS, you need an external switch to break these 3 connections, and instead feed GPS data only. I'm actually not sure how to do that. For an external GPS you drive the 3 lines directly from the GPS for 'stand alone' operation.
PS For the blue lights showing gpss and GPSV data coming in, I'm pretty sure you can select, in the Trio set up menu, whether you want these lights to blink or burn steadily.
PPS There is no "no" choice. If that's what you want disengage the autopilot or turn off Hnav or Vnav as desired.
PPPS My memory is dim here, but as I recall, as a safety feature, vertical modes will not engage until you are above stall speed plus a bit (you program the speed).

 

[ngxflyer213]

Bob

Thanks for your quick reply.

I guessed that was the procedure to engaging the AP, but could not find any reference in the manuals about it.

I do have the 3 wires to the Trio, but have not yet installed a selector switch for either ARINC 429 plus RS232 or RS232 alone to feed to AP. The Trio manual shows how to wire one in.

The Sport has an internal WASP certified GPS receiver so I think that will follow the GS. It also has the synthetic vision installed.

Thanks for the info about vertical mode not being active is below stall speed. I didn't think of that. Do you think I could use a pitot/static tester to show an airspeed above stall to test the vertical modes such as climb/descend to new altitude in VS or AS modes on the ground? The GPSV light only blinks now, but like you said is probably inhibited by the lack of airspeed.

I do not see the control sticks respond to the EFIS commands when the Flight Director bars are moving and following HDG or VOR commands. I think the AP should respond with the GPSS blue light illuminated. They do move correctly when commanded in the CRS mode of the Trio by rotating the encoder knob.

again thanks

Dave

 

[BobTurner]

Bob

Thanks for your quick reply.


The Sport has an internal WASP certified GPS receiver so I think that will follow the GS.

again thanks

Dave

No it won't. To follow a GPS glide slope (e.g., an LPV approach) you need an IFR certified (TSO) GPS, with its huge database. Also a huge cost.
But if you have an ILS receiver, it should follow that GS, but not in stand-alone mode. You need to run it thru the efis.

 

[ngxflyer213]

You are correct. The Sport has no data base to fly procedures.

We have a Val Nav2000 & Comm connected to the Sport as a SL-30 on a RS232 buss, so like you said it should follow the GS, but would not be IFR certified. The Sport also has the synthetic approach for SAP with HITS.

I have installed Sport in a RV-6a. We are at the stage of runup and taxi test. I just started learning and testing all electronic. We hope to fly it in the spring.

 

[BobTurner]

We have a Val Nav2000 & Comm connected to the Sport as a SL-30 on a RS232 buss, so like you said it should follow the GS, but would not be IFR certified.

I see things like this all the time. For part 91 operations, there is no requirement that VOR or ILS equipment meet TSO standards, which is what people usually mean when they say "certified". You do still have to do the 30 day VOR test to be legal (even though the SL-30 manual says, yes, you need to test, but it will never fail!) but otherwise it is legal to operate IFR with this equipment.
Just a few things: IFR GPS, transponders, ELTs, ADSB-out, have to "meet the performance standards" of a TSO.